Shoe-sewing machine



Dec. 23, 1924. 2 1,520,275

l F. E. BERTRAND SHOE SEWING MAC'PZLNE Original Fi1ed`Apri '7, 1916 2 Sheets-Sheet 1 igg. fr

Dec. 23, 1924. r 1,520,275

F. E. BERTRAND SHOE SEWING MACHINE Original Filed April '7, 1916 2 Sheets-Sheet 2 Patented Dec. 233, 1924.

STATES FREDERIC E. BERTRAND, OF LYNN, MASSACHUSETTS, ASSIGNOR T'O UNITED SHOE MACHINERY CORPRATION, OF PETERSON, NEVI' JERSEY, A CORPORATION OF NEW JERSEY.

Uriginal application led April '7, 1916, Serial No. 89,560. Divided and this application led November To a-ZZ 'whom t may concern Be it known that I, Fniinnnro E. BER- TRAND, a citizen of the United States, residing at Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Shoe- Sewing Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to sewing machines and more particularly to thread tensioning devices for shoe sewing machines of the type employing a curved hook needle adapted for fair stitching mock welts and stitched down shoes.

rllhe object of the present invention is to provide a novel and improved thread tensioning device for sewing machines which is simple in construction and efficient in operation.

rlhe features of the present invention comprise certain constructions, arrangements and combinations of parts hereinafter described and claimed, the advantages of which will be obvious to those skilled in the art.

rlhe several features of the present invention will be clearly understood from the following description and accompanying drawings in which:

Figure 1 is a side elevation looking from thel right of a shoe sewing machine embodying the features of the invention in their preferred form; Fig. 2 is a front elevation of a portion of the machine illustrated in Fig. 1; and Fig. 3 is a detail side elevation partly in section of portions of the thread tensioning devices.

rihe machine illustrated in the drawings is a chain stitch shoe sewing machine particularly designed for sewing the out-turned upper to the sole of a stitched down shoe. rihe machine is provided with a curved hook needle 2, a looper t, a heating chamber or web 6, a work support 8, a presser foot 10 and a presser footactuating rod 12 connected to a treadle so that the depression of the treadle depresses the rod which through connecting mechanism raises the presser Serial No. 339,649.

foot, and when the treadle is released the rod is moved upwardly and the presser foot is caused to engage the work. The parts above described may be and preferably are the same as the corresponding parte of the machine illustrated and described in applicants co-pending application Serial No. 89,560, filed April 7, 1916, of which the present application constitutes a division and to which reference may be had for a full and complete description of these parts of the machine.

rllhe illustrated machine is provided with a take-up comprising a take-up thread truck i4- carried on the outer end of a take-up arm 16 of a bellcrank lever, the hub 18 of which is fulcrumed on a hollow stud 2O journaled in bearings formed in arms projecting forwardly from a bracket secured to the machine frame. The other arm 22 of the bellcrank lever is connected bv a iink 24 to the slotted lower end of an arm 26 of a take-up lever of bellcrank form pivoted at 28 on an upright rising from the base of the machine. The other arm of the take-up lever extends rearwardly and carries a. cam roll which engages a cam path formed in the outer side of a cam 3() carried by the main shaft 32 of the machine. After the thread is drawn from the waX pot of the machine, it passes around a large thread truck or tension wheel Sli mounted on a shaft 36 supported in the hollow stud 20, and thence over two small pulleys or thread trucks d() and 12 which form part of the auxiliary take-up, to the truck 14, from whence it passes under a truck 4:4 to the looper. rlhe auxiliary take-up comprises a lever 4i@ pivoted at 48 on the machine frame, and on one end supports a pin on which the thread truck 4t2 is pivoted. The other end of the auxiliary take-up lever receives one end of a lightly tensioned spring 50, the other end of which is secured to the machine frame. A secondary compression spring 52, more heavily tensioned than the spring 50, is received in a chamber 54: formed on the machine frame, one end of the spring 52 pressing against a shoulder of a plunger 56 adapted to reciprocate in the chamber 54 and the other end of the spring taking against a nut 58 threaded in the open end of the chamber. The nut 58 affords means by which the tension of the spring 52 may be regulated. The movement of the auxiliary take-up lever A6 under the force of the spring 50 is limited by a stop pin 60.

It will be observed from an inspection of the drawings that the tension wheel 34 and the thread trucksv ofthe take-up and auxiliary take-up as well as the truck 44; are located and operate Vin close proximity to the heatingplate formi-ng the right: handl wall or surface of the heated chamber or web 6. By means of this construction the radiation `from the heating plate keeps the waxedctliread as it passes over the trucks on its way to the needle in a pliable and eas ilyl workablel condition.

In addition tothe tension wheel 34, the tension mechanism comprises a brake strap 62-'which makes one coinpletefturn around a drum-1641 .fast on the outer end of the shaft 36, on the other end of which the tension wheel 34 is fixed; One end of the brake strap is securedfto the frame of the machine, and the other end is secured to an eye of a bolt 66lo'osely receivedin-a hole in aL tension i vlever 68 pivoted on the machine frame. By arranging. the brake strap so that it makes one'completeturn' around the drum 64, the lines of' stress upon it'svends actin opposite 1 directions.v The free end of the tension lever upper endlof the bolt 66and securediii position thereon by a nut, by4 which the tension"l of the spr-ing may be regulated, tends to 'maintain'the bolt 66in raised positionv and imposes on the brake strap the strainl requisite to maintain the requiredV ainount'of tension on-the thread. It will be observed by the const-ructionV and arrangement of the lparts of the tension device that the pull exerted upon the brake strap is suchthat no cramping strain is imposed upon the shaft' 36 because the strain is evenly distributed `over the periphery of the pulley 6 4, and yet an Veffective clampingvstrani or gripping action isrimposed upon the shaft 36 and the tension'wheel 34. The relative arrangement of the-tension lever 68 andthe Apresser foot rod isfsuch that, when-tlie operator presses" the tre-adleconnectedwith the presser foot* rod, upon1 the completiony of the sewingoperation, the downward movement of the presser foot rod brings nuts 76 threaded on the rod into engagement with the upper surface of the free end of the tension lever, thereby depressing it against the upward action of the springl 70 andrelieving the tension strap of the strain of the spring 74 to permit the operator to remove the shoe with the thread attached to it from the` machine. The space between the nuts 7e midline upper side of the free end of the tension lever is such that, when at the completion of each feeding movement the presserv footrod4 descends andthe presser foot is raised to permit the return of the feed carriage, the nuts do not come into Contact with the tension lever and", consequently, the' uniform tension exerted by the` tension devicel is not 'disI turbed; Y Y

The nature and'scopeof thep-resent invention having' been indicated: and a machine embody-ing' the several features ofv the' present invention intheir preferred f'orm havingbeen specifically described, what is'claimed'V is:

l. A sewin-gmachine having, in combina-V tion; stitchforming devices-,1a tension wheel, a drum' connected therewith', a brake Strap embracing. ther drum connected atI oneT end: to a stationary part ofi the'machine, andyield'- ing.v means connected withy theV other end of the strapfor exerting a strain upon it, the ends-'of t'li'estrap'being. disposed in" opposite directions: l

2;' A sewing machine having', in combination, stitchv forming devices, a'y shaft, a' tension wheel mounted on the shaft, an os'cil-` latory take-up arm' p'ivot'ed on: the shaft, a

friction drumf secured to the shaft, a' brake` mechanism acting-upon the drum a'nd'means for supplyingheat t'o the tension wheel and take-up ar'm.

3. A sewing machine having, in combinar tion, stitchlfor'ming devices,a heating plate, a tension wheel, a takeupA arin imountea'd'con#l centric with the axis ofV the t'eii'sion'` wheel;- and a take-up truck mounted onthe take-up arm, the tension wheel and take-up" truck operating in close proximity to the" plate;

4; Ay sewing machine having,i`ncombination, stitch formingdevices, a heatingl plate', a tens-ionwheel and af take-up truck' operatingin clse proximity to'the'plate, a drum, a shaft supporting on one endI thedrurii'andA on the other end the tensionwheel,l abrake mec-liai'iism for' the drum,fandatake-uparm for supporting theA take-up truckpivotally mounted on the shaft between the" tension wheel and the drum.'

5. A shoe sewing'machinehaving, vin coinbination, stitch forming devices,- ab worksupport, a presser fo'ot, allpressei* foot actuating rod, al tension" wheel, and a' brake mechanism therefor''includingl aftension lever arranged tobe moved by thepresser` footz actuating rod to release'the brak'efmechanism when the rod is actuated to raise the presser foot from the Work support for the insertion or removal of Work.

6. A shoe sewing,` machine. having, in oom- 5 binaton, stitch forming devices, a Work support, a presser foot, presser foot actuating mechanism, a thread tension Wheel, a brake for restraining the rotation of the tension Wheel, a treadle controllable rod, and oonneotions between the rod and the presser foot actuating mechanism and the brake actuated by the rod to raise the presser foot and rele-ase the brake upon a movement of the rod.

FREDERIC E. BERTRAND 

